Thermally stable biuret and isocyanurate based surface modifying macromolecules and uses thereof

ABSTRACT

The invention relates to surface modifying macromolecules (SMMs) having high degradation temperatures and their use in the manufacture of articles made from base polymers which require high temperature processing. The surface modifier is admixed with the base polymer to impart alcohol and water repellency properties.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/060,542, filed Feb. 24, 2011, with a 371(c) date of May 5, 2011,which is the U.S. National Stage of International Application No.PCT/US2009/055418, filed Aug. 28, 2009, which claims benefit from U.S.Provisional Application No. 61/092,667, filed Aug. 28, 2008, each ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The invention relates to surface modifying macromolecules (SMMs) havinghigh degradation temperatures and their use in the manufacture ofarticles made from base polymers which require high temperatureprocessing.

Various fluorochemicals have been used to impart water and oilrepellency, as well as soil resistance, to a variety of substrates.These fluorochemicals have most often been applied topically (forexample, by spraying, padding, or finish bath immersion). The resultingrepellent substrates have found use in numerous applications where waterand/or oil repellency (as well as soil resistance) characteristics arevalued, such as in protective garments for medical technicians andlaboratory workers. The repellent substrates can be used, for example,where it is desirable to prevent passage of blood, blood-bornepathogens, and other body fluids across the fabric (i.e., to blockexposure to chemically toxic or infectious agents), and to reduceexposure to low surface tension chemicals, such as alcohols, ketones,and aldehydes.

Medical care garments and protective wear garments used commercially areoften fully or partially constructed of extruded articles (e.g.,thermoplastic films, thermoplastic fibers, fibrous non-woven materials,thermoplastic foam materials, etc.). Examples of these products are insurgical drapes, gowns and bandages, and protective wear garments (e.g.,workers overalls, facemasks, and labcoats, among others). Thesematerials require high temperature processing conditions often exceeding200° C.

Many fluorochemicals lack the requisite thermal stability to beprocessed at temperatures above 200° C. (for example, in melt spunapplications where high extrusion temperatures often exceeding 275-300°C. are involved).

Thus, there remains a need for thermally s′ additives which can be usedin admixture with base polymers that require high temperature processingto impart water, oil repellency, and/or lower surface energy.

SUMMARY OF THE INVENTION

The invention provides surface modifying macromolecule (SMM or surfacemodifier) additives having high degradation temperatures. These SMMs areuseful in the manufacture of articles made from base polymers whichrequire high temperature processing.

Accordingly, in a first aspect the invention features a surface modifierof formula (I):

In formula (I), A is a soft segment including hydrogenatedpolybutadiene, poly(2,2 dimethyl-1-3-propylcarbonate), polybutadiene,poly(diethylene glycol)adipate, diethylene glycol-ortho phthalicanhydride polyester, poly (hexamethyhlenecarbonate)diol, hydroxylterminated polydimethylsiloxanes (PrO-PDMS-PrO) block copolymer,poly(tetramethyleneoxide)diol, hydrogenated-hydroxyl terminatedpolyisoprene,poly(ethyleneglycol)-block-poly(propyleneglycol))-block-poly(ethyleneglycol), 1,12-dodecanediol, poly(hexamethylene carbonate),poly(ethylene-co-butylene), 1,6-hexanediol-ortho phthalic anhydridepolyester, neopentyl glycol-ortho phthalic anhydride polyester, orbisphenol A ethoxylate; or 1,6-hexanediol-ortho phthalic anhydridepolyester; B is a hard segment including a urethane trimer or biurettrimer; G is a surface active group; and n is an integer from 0 to 10(e.g., 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10).

Surface modifiers of formula (I) can have a thermal degradationtemperature of at least 200, 205, 210, 215, 220, 225, 230, 235, 240,245, 250, 255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310,315, 320, 325, 330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380,385, 390, 395, 400, 405, 410, 415, 420, 425, 430, 435, 440, 445, or even350° C. In certain embodiments, the surface modifier has a thermaldegradation temperature of between 200 and 250° C., 220 and 250° C., 220and 300° C., 220 and 280° C., 220 and 260° C., 240 and 300° C., 240 and280° C., 240 and 260° C., 260 and 300° C., 260 and 280° C., 200 and 345°C., 220 and 345° C., 250 and 345° C., 275 and 345° C., 300 and 450° C.,320 and 450° C., 340 and 450° C., 360 and 450° C., 380 and 450° C., 400and 450° C., 420 and 450° C., 300 and 430° C., 300 and 410° C., 300 and400° C., 300 and 380° C., 300 and 360° C., 300 and 340° C., and 300 and320° C.

In certain embodiments, the soft segment has a number average molecularweight (M_(n)) of 500 to 3,500 Daltons. In some embodiments, M_(n) isbetween 500 to 1000, 500 to 1250, 500 to 1500, 500 to 1750, 500 to 2000,500 to 2250, 500 to 2500, 500 to 2750, 500 to 3000, 500 to 3250, 1000 to1250, 1000 to 1500, 1000 to 1750, 1000 to 2000, 1000 to 2250, 1000 to2500, 1000 to 2750, 1000 to 3000, 1000 to 3250, 1000 to 3500, 1500 to1750, 1500 to 2000, 1500 to 2250, 1500 to 2500, 1500 to 2750, 1500 to3000, 1500 to 3250, or 1500 to 3500 Daltons. In still other embodiments,the surface active group has a molecular weight of between 100-1,500Daltons. In still other embodiments, the surface active group has amolecular weight of between 100-1,500,100-1,400,100-1,300,100-1,200,100-1,100,100-1,000,100-900, 100-900, 100-800, 100-700, 100-600,100-500, 100-400, 100-300, or 100-200 Daltons.

Surface active groups include, without limitation,polydimethylsiloxanes, hydrocarbons, polyfluoroalkyl, fluorinatedpolyethers, and combinations thereof. Desirably, the surface activegroup is a polyfluoroalkyl, such as 1H,1H,2H,2H-perfluoro-1-decanol((CF₃)(CF₂)₇CH₂CH₂OH); 1H,1H,2H,2H-perfluoro-1-octanol((CF₃)(CF₂)₅CH₂CH₂OH); 1H,1H,5H-perfluoro-1-pentanol (CHF₂(CF₂)₃CH₂OH);and 1H,1H, perfluoro-1-butanol ((CF₃)(CF₂)₂CH₂OH), or mixtures thereof(e.g., mixtures of (CF₃)(CF₂)₇CH₂CH₂OH and (CF₃)(CF₂)₅CH₂CH₂OH), or aradical of the general formulas CF₃(CF₂)_(r)CH₂CH₂— wherein r is 2-20,and CF₃(CF₂)_(s)(CH₂CH₂O)_(χ)— wherein χ is 1-10 (e.g., 1, 2, 3, 4, 5,6, 7, 8, 9, or 10) and s is 1-20 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, or 20).

In certain embodiments, n is an integer from 0-5 (e.g., 0, 1, 2, 3, 4,or 5). Desirably, n is 0, 1, or 2.

The surface modifiers of the invention can have a theoretical molecularweight of less than 25 kDa, desirably less than 20 kDa, 18 kDa, 16 kDa,15 kDa, 14 kDa, 13 kDa, 12 kDa, 11 kDa, 10 kDa, 8 kDa, 6 kDa, or even 4kDa. In other embodiments, the surface modifiers of the invention have atheoretical molecular weight of 9 kDa, 8.5 kDa, 7.5 kDa, 7 kDa, 6.5 kDa,5.5 kDa, 5 kDa, 4.5 kDa, 3.5 kDa, 3 kDa, 2.5 kDa, 2 kDa, 1.5 kDa or 1kDa.

The surface modifiers of the invention can include from 5% to 35%, 10%to 35%, 5 to 30%, 10 to 30%, 5 to 20%, 5 to 15%, or 15 to 30% (w/w) ofthe hard segment; from 40 to 90%, 50 to 90%, 60 to 90%, 40 to 80%, or 40to 70% (w/w) of the soft segment; and from 25 to 55%, 25 to 50%, 25 to45%,25 to 40%, 25 to 35%, 25 to 30%, 30 to 55%, 30 to 50%, 30 to 45%, 30to 40%, 30 to 35%, 35 to 55%, 35 to 50%, 35 to 45%, 35 to 40%, 40 to55%, 40 to 50%, 40 to 45%, 45 to 55%, 45 to 50%, or 50-55% (w/w) of thesurface active group.

The invention also features an admixture including a surface modifier ofthe invention admixed with a base polymer. In certain embodiments, thebase polymer is selected from polypropylenes, polyethylenes, polyesters,polyurethanes, nylons, polysilicones, polystyrenes, poly(methylmethacrylates), polyvinylacetates, polycarbonates,poly(acrylonitrile-butadiene)s, polyvinylchloride, and blends thereof.For example, SMMs including hydrogenated polybutadiene can be admixedwith polypropylenes or polyethylenes, SMMs including poly(2,2dimethyl-1-3-propylcarbonate) can be admixed with polyurethanes, andSMMs including poly(ethylene-co-butylene) can be admixed withpolyethylenes or polyurethanes.

The admixtures can be prepared by (i) combining the base polymer and thesurface modifier to form a mixture, and (ii) heating the mixture above200° C., 220° C., 250° C., 270° C., 300° C., 320° C. or 350° C. Theadmixtures of the invention contain from 0.05% to 20%, 0.05% to 15%,0.05% to 13%, 0.05% to 10%, 0.05% to 5%, 0.05% to 3%, 0.5% to 15%, 0.5%to 10%, 0.5% to 6%, 0.5% to 4%, 1% to 15%, 1% to 10%, 1% to 8%, 1% to6%, 1% to 5%, 2% to 5%, or 4% to 8% (w/w) surface modifier.

The invention further features an article formed from an admixture ofthe invention. Articles that can be formed using the admixtures of theinvention include, without limitation, surgical caps, surgical sheets,surgical covering clothes, surgical gowns, masks, gloves, surgicaldrapes, filter (e.g., part of a respirator, water filter, air filter, orface mask), cables, films, panels, pipes, fibers, sheets, andimplantable medical device (e.g., a cardiac-assist device, a catheter, astent, a prosthetic implant, an artificial sphincter, or a drug deliverydevice).

The invention also features a method for making an article by (i)combining a base polymer with a surface modifier of the invention toform a mixture, and (ii) heating the mixture to at least 150° C.Desirably, the mixture is heated to a temperature of between 250° C. and450° C.

The invention further features a method for increasing the thermaldegradation temperature of a surface modifier of formula (I):

where A is a soft segment; B is a hard segment including a urethanetrimer or biuret trimer; each G is a surface active group, n is aninteger between 0-10, and

where the method includes the steps of:

(a) reacting a urethane trimer or biuret trimer with a monohydroxylicsurface active group; and

(b) reacting the product of (a) with a soft segment;

where step (a) or (b) is performed in the presence of a bismuth (e.g, abismuth carboxylate) catalyst.

In certain embodiments the diol soft segment is selected fromhydrogenated-hydroxyl terminated polybutadiene, poly(2,2dimethyl-1-3-propylcarbonate)diol, poly(hexamethylene carbonate)diol,poly(ethylene-co-butylene)diol, hydroxyl terminated polybutadienepolyol, poly(diethylene glycol)adipate, poly(tetramethylene oxide)diol,diethylene glycol-ortho phthalic anhydride polyester polyol,1,6-hexanediol-ortho phthalic anhydride polyester polyol, neopentylglycol-ortho phthalic anhydride polyester polyol, and bisphenol Aethoxylate diol. In certain embodiments, step (a) includes reacting adiisocyanate with hydrogenated-hydroxyl terminated polybutadiene orpoly(2,2 dimethyl-1-3-propylcarbonate)diol. In other embodiments, thediisocyanate is selected from 3-isocyanatomethyl, 3,5,5-trimethylcyclohexylisocyanate; 4,4′-methylene bis(cyclohexyl isocyanate);4,4′-methylene bis(phenyl) isocyanate; toluene-2,4 diisocyanate); andhexamethylene diisocyanate. Monohydroxylic surface active groups usefulin making the SMMs of the invention include any disclosed herein. Incertain embodiments the monohydroxylic surface active group is selectedfrom compounds of the general formula CF₃(CF₂)_(r)CH₂CH₂OH wherein r is2-20, and CF₃(CF₂)_(s)(CH₂CH₂O)_(χ)CH₂CH₂OH wherein χ is 1-10 (e.g., 1,2, 3, 4, 5, 6, 7, 8, 9, or 10) and s is 1-20 (e.g., 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20.

The invention also features a surface modifier of formula (II):

where A is a soft segment; B is a hard segment including a urethanetrimer or biuret trimer; B′ is a hard segment including a urethane; andeach G is a surface active group; and where n is an integer between 0 to10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10) and the surface modifier hasa thermal degradation temperature of between 250° C. and 450° C. Surfacemodifiers of formula (II) can have a thermal degradation temperature ofat least 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250, 255,260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, 320, 325,330, 335, 340, 345, 350, 355, 360, 365, 370, 375, 380, 385, 390, 395,400, 405, 410, 415, 420, 425, 430, 435, 440, 445, or even 350° C. Incertain embodiments, the surface modifier has a thermal degradationtemperature of between 200 and 250° C., 220 and 250° C., 220 and 300°C., 220 and 280° C., 220 and 260° C., 240 and 300° C., 240 and 280° C.,240 and 260° C., 260 and 300° C., 260 and 280° C., 200 and 345° C., 220and 345° C., 250 and 345° C., 275 and 345° C., 300 and 450° C., 320 and450° C., 340 and 450° C., 360 and 450° C., 380 and 450° C., 400 and 450°C., 420 and 450° C., 300 and 430° C., 300 and 410° C., 300 and 400° C.,300 and 380° C., 300 and 360° C., 300 and 340° C., and 300 and 320° C.

Surface modifiers of Formula (II) can be used in any of the methods,articles, and admixtures of the invention.

The invention also features a method of increasing repellency byannealing a surface modifier with a base polymer where the annealingtemperature is between 50° C. and 75° C. and the annealing time isbetween 1-24 hours.

In some embodiments, the surface modifier has the following structure

where A is a soft segment; B is a hard segment including a urethanetrimer or biuret trimer; B′ is a hard segment including a urethane; eachG is a surface active group; n is an integer between 0 to 10 (e.g., 1,2, 3, 4, 5, 6, 7, 8, 9, or 10) and the surface modifier has a thermaldegradation temperature of between 250° C. and 450° C. In certainembodiments, the surface modifier has a thermal degradation temperatureof between 200 and 250° C., 220 and 250° C., 220 and 300° C., 220 and280° C., 220 and 260° C., 240 and 300° C., 240 and 280° C., 240 and 260°C., 260 and 300° C., 260 and 280° C., 200 and 345° C., 220 and 345° C.,250 and 345° C., 275 and 345° C., 300 and 450° C., 320 and 450° C., 340and 450° C., 360 and 450° C., 380 and 450° C., 400 and 450° C., 420 and450° C., 300 and 430° C., 300 and 410° C., 300 and 400° C., 300 and 380°C., 300 and 360° C., 300 and 340° C., and 300 and 320° C.

In some embodiments, the annealing temperature is 50° C., 51° C., 52°C., 53° C., 54° C., 54.4° C., 55° C., 56° C., 57° C., 58° C., 59° C.,60° C., 61° C., 62° C., 63° C., 64° C., 65° C., 70° C., or 75° C. Inother embodiments, the annealing time is 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,11, or 12 hours.

As used herein, “surface modifier” refers to the compounds describedherein or in U.S. Pat. No. 6,127,507 or in U.S. patent application Ser.No. 12/002,226, each of which is herein incorporated by reference. Asurface modifier can also be described as a relatively low molecularweight polymer or oligomer containing a central portion of less than 20kDa and covalently attached to at least one surface active group. Thelow molecular weight of the surface modifier allows for diffusion amongthe macromolecular polymer chains of a base polymer.

By “surface active group” is meant a lipophilic group covalentlytethered to a surface modifier. The surface active group can bepositioned to cap one or both termini of the central polymeric portionof the surface modifier or can be attached to one or more side chainspresent in the central polymeric portion of the surface modifier.Examples of surface active groups include, without limitation,polydimethylsiloxanes, hydrocarbons, polyfluoroalkyl, fluorinatedpolyethers, and combinations thereof.

As used herein, the term “thermal degradation temperature” refers to thetemperature at which there is an onset of weight loss (a first onsetrepresenting a small weight loss, followed by a second onset at aconsiderably higher temperature representing the major fraction of theweight) of the SMM during thermographic analysis.

The thermal stability of the SMMs have also been tested under rigorousheating conditions e.g. 220, 260 and 300° C. for 10 and 25 minutes andthe corresponding weight losses have been determined at thesetemperatures. These are typical temperatures experienced by polymersduring processing at conditions that require high temperatures. Theprolonged heating times of 10 and 25 minutes under isothermal conditionsare rather harsh where in reality the polymers would only experienceshorter residence time during actual processing (e.g., <5 minutes).Additionally, the prolonged heating times are to test the integrity ofthese surface modifiers and gauge the extent of degradation through theweight losses occurring at 10 and 25 minutes. This analysis is describedin Example 1.

Other features and advantages of the invention will be apparent from theDrawings, Detailed Description, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 a-1 n show the chemical structures of SMM1-SMM14.

FIG. 2 is a graph depicting the High Resolution Thermogravimetricprofile of SMM2 indicating a first onset at a degradation temperatureT_(d1)=284° C., representing a minor weight loss (−1%) followed by amajor weight loss at T=396° C. (−61%).

FIG. 3 is a graph depicting the High Resolution Thermogravimetricprofile of SMM3 indicating a first onset at a degradation temperatureT_(d1)=295° C., representing a minor weight loss (−1.1%) followed by amajor weight loss at T_(d2)=405° C. (−55.31%).

FIG. 4 is a graph depicting the High Resolution Thermogravimetricprofile of SMM5 indicating a first onset at a degradation temperatureT_(d1)=306° C., representing a minor weight loss (−1.34%) followed by amajor weight loss at T=433° C. (−37.82%).

FIG. 5 is a graph depicting the High Resolution Thermogravimetricprofile of SMM7 indicating a first onset at a degradation temperatureT_(d1)=295° C., representing a minor weight loss (−2.29%) followed by amajor weight loss at T_(d2)=365° C. (−31%).

FIG. 6 is a graph depicting the High Resolution Thermogravimetricprofile of SMM8 indicating a first onset at a degradation temperatureT_(d1)=290° C., representing a minor weight loss (−0.43%) followed by amajor weight loss at T_(d2)=415° C. (−56.09%).

FIG. 7 is a graph depicting the High Resolution Thermogravimetricprofile of SMM10 indicating a first onset at a degradation temperatureT_(d1)=293° C., representing a minor weight loss (−1.30%) followed by amajor weight loss at T_(d2)=347° C. (−37.70%).

FIG. 8 is a graph depicting the High Resolution Thermogravimetricprofile of SMM11 indicating a first onset at a degradation temperatureT_(d1)=294° C., representing a minor weight loss (−2.80%) followed by amajor weight loss at T_(d2)=339° C. (−40.16%).

FIGS. 9A, 9B, and 9C show thermal data and polymer characterizationdata, including TGA and EA results, for SMM1-SMM14.

FIG. 10 is a plot showing the surface modification of various basepolymers, e.g., polyurethane, siloxane, polypropylene, and polyvinylchloride, when admixed with SMM and the percent fluorine on the surfaceof these polymers after XPS analysis.

FIG. 11 shows the IPA repellency of surface-modified meltblown (MB)fabric as function of annealing time & temperature.

FIG. 12 shows the IPA repellency of surface modified MB fabric after asterilization cycle.

FIG. 13 illustrates the repellency of treated and untreated nonwovenfabric.

FIG. 14 illustrates repellency achieved on MB fabrics after brief,direct contact with hot plate surfaces at 100-130° C.

FIG. 15 shows repellency to alcohol solutions with concentrations ashigh as 80 vol % IPA can be achieved on spunbond fabrics modified withSMMs.

DETAILED DESCRIPTION

The methods and compositions of the invention feature thermally stableSMMs useful for the surface modification of a range of commerciallyavailable base polymers which are processed at high temperatures, suchas polypropylene, polyethylene, polyesters, nylon, polyurethanes,silicones, PVC, polycarbonates, polysulfones, and polyethersulfones,among others.

The invention features a series of SMMs based on biurets andisocyanurates of hexamethylene diisocyanate and isophorone diisocyanatehaving enhanced fluorination. The SMMs also possess high temperaturestability at temperatures >200° C. and compatibility with base polymers(e.g., polyurethanes, polyethylenes, polypropylenes, polysiloxanes,polyvinyl chlorides, and polycarbonate) and may be used in themanufacture of articles for both implantable and non-implantabledevices.

To provide the required functional properties, the SMM additives in thisinvention are added into the desired base polymer during processingwhether it is being extruded, meltspun, spunbond, solvent spun, orinjection molded. The additives can impart material properties thatinclude, but are not limited to: (a) heat and chemical resistance,mechanical strength, (b) oil and water repellency, (c) surfacesmoothness, (d) resistance to hydrocarbons, acids, polar solvents andbases, (e) dimensional stability at high temperatures, (f)hydrophobicity, (g) non-adhesive characteristics, (h) hydrophilicitycharacteristics, (i) biocompatibility, and (j) surface hardness.

Surface modifiers of the invention can be described by Formula (I):

where in Formula (I)

-   -   (i) A is a soft segment comprising two hydroxyl end groups that        are each covalently bound to B;    -   (ii) B is a hard segment comprising urethane trimer or biuret        trimer; and    -   (iii) each G is a surface active group;

where n is an integer between 0 to 10.

Soft Segments

Exemplary soft segments include, but are not limited to:hydrogenated-hydroxyl terminated polybutadiene (HLBH), poly(2,2dimethyl-1-3-propylcarbonate)diol (PCN), poly(hexamethylenecarbonate)diol (PHCN), poly(ethylene-co-butylene)diol (PEB), hydroxylterminated polybutadiene polyol (LBHP), poly(diethylene glycol)adipate(PEGA), poly(tetramethylene oxide)diol (PTMO), diethyleneglycol-orthophthalic anhydride polyester polyol (PDP),1,6-hexanediol-ortho phthalic anhydride polyester polyol (SPH),neopentyl glycol-orthophthalic anhydride polyester polyol (SPN),bisphenol A ethoxylate diol (BPAE), hydrogenated hydroxyl terminatedpolyisoprene (HHTPI), poly(2-butyl-2-ethyl-1,3-propylcarbonate)diol,hydroxylterminated polydimethylsiloxanes block copolymer (C22 orPrO-PDMS-PrO), polypropylene oxide (PPO), and polycaprolactone (PCL).

Suitable hard segments include biuret and urethane trimers (e.g.,biurets and isocyanurates of hexamethylene diisocyanate and isophoronediisocyanate). Exemplary trimers suitable for use as hard segments areavailable as Desmodur products from Bayer. Exemplary Desmodur productsuseful in the macromolecules of the invention include:

Surface Active Groups

Surface active groups include, without limitation,polydimethylsiloxanes, hydrocarbons, polyfluoroalkyl, fluorinatedpolyethers, and combinations thereof. Desirably, the surface activegroup is a polyfluoroalkyl, such as 1H,1H,2H,2H-perfluoro-1-decanol;1H,1H,2H,2H-perfluoro-1-octanol; 1H,1H,5H-perfluoro-1-pentanol; and1H,1H, perfluoro-1-butanol, or mixtures thereof or a radical of thegeneral formulas CH_(m)F_((3-m))(CF₂)_(r)CH₂CH₂— orCH_(m)F_((3-m))(CF₂)_(s)(CH₂CH₂O)_(χ)—, where m is 0, 1, 2, or 3; χ isan integer between 1-10; r is an integer between 2-20; and s is aninteger between 1-20.

Surface modifiers of the invention can be prepared as described in U.S.Pat. No. 6,127,507, incorporated herein by reference, and in Examples1-6. Surface modifiers, according to the invention, can be selected in amanner that they contain a soft segment selected to impart thermalstability. Such soft segments can include hydrogenated-hydroxylterminated polybutadiene, poly(2,2 dimethyl-1-3-propylcarbonate)diol,hydroxyl terminated polybutadiene polyol, poly(diethyleneglycol)adipate, diethylene glycol-ortho phthalic anhydride polyesterpolyol, and 1,6-hexanediol-ortho phthalic anhydride polyester polyol.The invention also includes methods for increasing the thermal stabilityof an SMM using the synthetic methods described herein to improve theircompatibility with the conditions characteristic of base polymerprocessing techniques. Desirably, the SMMs of the invention are preparedusing catalysts that do not include tin, such as bismuth catalysts(e.g., bismuth carboxylate catalysts). It has been shown that residualtin in the final product is cytotoxic, and small amounts can alsocatalyze and accelerate the degradation of an SMM upon heating, leadingto reduced thermal stability. The use of bismuth catalysts in thesynthesis of urethanes is well known in the art (see, for example, U.S.Pat. Nos. 4,584,362; 4,742,090; 4,788,083; 5,064,871; and 6,353,057).Bismuth is non cytotoxic and environmentally friendly. The use ofbismuth catalysts increases the biocompatibility of the polymers andleads to improved reaction kinetics, producing products that havenarrower molecular weight distributions and are more thermally stable.As with tin, residual bismuth levels must be kept to a minimum toprevent depolymerization upon heating. Bismuth catalysts that can bepurchased for use in the methods of the invention include Bi348, Bi221,and Bi601 (bismuth carboxylates, King Industries, Norwalk Conn.), aswell as bismuth tris(neodecanoate) (NeoBi 200, Shepherd Chemicals). Thesoft segment of the surface modifier can function as an anchor for thesurface modifier within the base polymer substrate upon admixture. Thesurface active groups are responsible, in part, for carrying the surfacemodifier to the surface of the admixture, where the surface activegroups are exposed on the surface. As a result, once the surfacemodifier at the surface of any of the articles described herein isactivated by contact with another surface, it is continuouslyreplenished by the migration of surface modifier from the admixture tothe surface. The latter process is believed to be driven by tendencytowards establishing a low surface energy at the mixture's surface. Whenthe balance between anchoring and surface migration is achieved, thesurface modifier remains stable at the surface of the polymer whilesimultaneously altering surface properties.

Suitable base polymers (which can be either thermoplastic or thermoset)include, without limitation, commodity plastics such as poly(vinylchloride), polyethylenes (high density, low density, very low density),polypropylene, and polystyrene; engineering plastics such as, forexample, polyesters (e.g., poly (ethylene terephthalate) andpoly(butylene terephthalate)), polyamides (aliphatic, amorphous,aromatic), polycarbonates (e.g., aromatic polycarbonates such as thosederived from bisphenol A), polyoxymethylenes, polyacrylates andpolymethacrylates (e.g., poly(methyl methacrylate)), some modifiedpolystyrenes (for example, styrene-acrylonitrile (SAN) andacrylonitrile-butadiene-styrene (ABS) copolymers), high-impactpolystyrenes (SB), fluoroplastics, and blends such as poly(phenyleneoxide)-polystyrene and polycarbonate-ABS; high-performance plastics suchas, for example, liquid crystalline polymers (LCPs), polyetherketone(PEEK), polysulfones, polyimides, and polyetherimides; thermosets suchas, for example, alkyd resins, phenolic resins, amino resins (e.g.,melamine and urea resins), epoxy resins, unsaturated polyesters(including so-called vinyl esters), polyurethanes, allylics (e.g.,polymers derived from allyldiglycolcarbonate), fluoroelastomers, andpolyacrylates; and blends thereof.

The base polymer is combined with a surface modifier of the invention toform an admixture. Thermoplastic polymers are more preferred in view oftheir melt processability. The thermoplastic polymers are meltprocessable at elevated temperatures (e.g., above 200° C., 240° C., 270°C., or even 300° C.). Desirable thermoplastic base polymers for use inthe admixtures of the invention include, without limitation,polypropylenes, polyethylenes, polyesters, polyurethanes, nylons,polystyrene, poly(methyl methacrylates), polyvinylacetates,polycarbonates, poly(acrylonitrile-butadiene), styrene,polyvinylchloride, and blends thereof.

The surface modifier is added prior to melt processing of the basepolymer to produce various articles. To form an admixture by meltprocessing, the surface modifier can be, for example, mixed withpelletized or powdered polymer and then melt processed by known methodssuch as, for example, molding, melt blowing, melt spinning, or meltextrusion. The surface modifier can be mixed directly with the polymerin the melt condition or can first be pre-mixed with the polymer in theform of a concentrate of the surface modifier/polymer admixture in abrabender mixer. If desired, an organic solution of the surface modifiercan be mixed with powdered or pelletized polymer, followed byevaporation of the solvent and then by melt processing. Alternatively,the surface modifier can be injected into a molten polymer stream toform an admixture immediately prior to extrusion into fibers, or anyother desired shape.

After melt processing, an annealing step can be carried out to enhancethe development of repellent characteristics of the base polymer. Inaddition to, or in lieu of, such an annealing step, the melt processedcombination can also be embossed between two heated rolls, one or bothof which can be patterned. An annealing step typically is conductedbelow the melt temperature of the polymer (e.g., at about 150-220° C.for up to 5 minutes in the case of polyamide). Alternatively, thefinished article can be subjected to a heated sterilization process(e.g., ethylene oxide sterilization (EtO sterilization) at 54.4° C.).

The surface modifier is added to thermoplastic or thermosetting polymerin amounts sufficient to achieve the desired repellency properties for aparticular application. Typically, the amount of surface modifier usedis in the range of 0.05-15% (w/w) of the admixture. The amounts can bedetermined empirically and can be adjusted as necessary or desired toachieve the repellency properties without compromising other physicalproperties of the polymer.

For example, where the base polymer-SMM admixture is processed toproduce melt-blown or melt-spun fibers, these fibers can be used to makenon-woven fabrics which have utility in any application where some levelof repellency is desired. For example, the SMMs of the invention can beused for medical fabrics, medical and industrial apparel, fabrics foruse in making clothing, home furnishings, and filtration systems, suchas chemical process filters or respirators. Other applications are inthe automotive and construction industries. The fabrics exhibit alcoholand water repellency characteristics. The fabrics can also exhibit oilrepellency (and soil resistance) characteristics under a variety ofenvironmental conditions and can be used in a variety of applications.

Non-woven webs or fabrics can be prepared by processes used in themanufacture of either melt-blown or spunbonded webs. For example, aprocess similar to that described by Wente in “Superfine ThermoplasticFibers,” Indus. Eng'g Chem. 48, 1342 (1956) or by Wente et al. in“Manufacture of Superfine Organic Fibers,” Naval Research LaboratoriesReport No. 4364 (1954) can be used. Multi-layer constructions made fromnon-woven fabrics enjoy wide industrial and commercial utility, forexample, as medical fabrics. The makeup of the constituent layers ofsuch multi-layer constructions can be varied according to the desiredend-use characteristics, and the constructions can comprise two or morelayers of melt-blown and spunbonded webs in many useful combinationssuch as those described in U.S. Pat. No. 5,145,727 (Potts et al.) andU.S. Pat. No. 5,149,576 (Potts et al.), the descriptions of which areincorporated herein by reference. In multi-layer constructions, thesurface modifier can be used in one or more layers to impart repellencycharacteristics to the overall construction.

Alternatively, the base polymer-SMM admixture is melt processed toproduce a desired shape using an appropriate mold.

Articles

The surface modifiers and admixtures of the invention can be used infilms and nonwoven applications, e.g., surgical drapes, gowns, facemasks, wraps, bandages, and other protective wear garments for medicaltechnicians (e.g. workers overalls, labcoats) require high temperatureprocessing often exceeding 200° C. in the form of extruded articles(e.g., thermoplastic films, thermoplastic fibers, fibrous nonwovenmaterials, thermoplastic foam materials, etc.) where processingtemperatures can reach a range of 250-300° C. The surface modifiers andadmixtures of the invention can also be used in implantable medicaldevices (e.g., central venous catheters to impart reduced occlusionproperties, and increased blood compatibility). The surface modifiersand admixtures of the invention may also be used in hollow fibermembrane filtration made from polyethylene, polypropylenes, orpolysiloxane base polymers for fluid or gas separation.

The surface modifiers and admixtures of the invention have the requiredhigh temperature stability during the processing in nonwoven fabricmanufacturing or the compatibility with the polymers that are used incatheter manufacture. The admixtures therefore can provide the requiredresistance to degradation at high temperatures while providing the waterand/or oil and/or alcohol repellency together with the desiredbiocompatible properties. The technology involves the incorporation ofthe SMMs into the base polymers which then bloom to the surface, thusmodifying the surface of the polymers but keeping the bulk propertiesintact. The base polymers now have a fluorinated surface with a highdegree of hydrophobicity.

Implanted Devices

Articles that may be formed from the admixtures of the invention includeimplanted devices. Implanted devices include, without limitation,prostheses such as pacemakers, electrical leads such as pacing leads,defibrillators, artificial hearts, ventricular assist devices,anatomical reconstruction prostheses such as breast implants, artificialheart valves, heart valve stents, pericardial patches, surgical patches,coronary stents, vascular grafts, vascular and structural stents,vascular or cardiovascular shunts, biological conduits, pledges,sutures, annuloplasty rings, stents, staples, valved grafts, dermalgrafts for wound healing, orthopedic spinal implants, orthopedic pins,intrauterine devices, urinary stents, maxial facial reconstructionplating, dental implants, intraocular lenses, clips, sternal wires,bone, skin, ligaments, tendons, and combination thereof. Percutaneousdevices include, without limitation, catheters of various types,cannulas, drainage tubes such as chest tubes, surgical instruments suchas forceps, retractors, needles, and gloves, and catheter cuffs.Cutaneous devices include, without limitation, burn dressings, wounddressings and dental hardware, such as bridge supports and bracingcomponents.

In a particular embodiment, admixtures that include a surface modifierthat includes a polysiloxane as a soft segment are used in themanufacture of catheters.

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how themethods and compounds claimed herein are performed, made, and evaluated,and are intended to be purely exemplary of the invention and are notintended to limit the scope of what the inventors regard as theirinvention.

The SMMs of the invention can be constructed by appropriate designcombinations of the hard segments (e.g., diisocyanates ortriisocyanates), central soft segments (e.g., diols), and thefluorinated end-capping groups to form a wide range of polyurethaneswith the desired high degradation temperatures, and specificallyemploying bismuth catalysts in the polymerization. These include, butare not limited to, the component reagents mentioned below.

Diisocyanates

-   HMDI=4,4′-methylene bis(cyclohexyl isocyanate)-   IPDI=Isophorone Diisocyanate-   TMXDI=m-tetramethylenexylene Diisocyanate-   HDI=Hexamethylene Diisocyanate    Triisocyanates (Hard Segments)-   Desmodur N3200 or Desmodur N-3200=hexamethylene diisocyanate (HDI)    biuret trimer-   Desmodur Z4470A or Desmodur Z-4470A=isophorone diisocyanate (IPDI)    trimer-   Desmodur N3300=hexamethylene diisocyanate (HDI) trimer:    Diols/Polyols (Soft Segments)-   HLBH=Hydrogenated-hydroxyl terminated polybutadiene,-   PCN=Poly (2,2 dimethyl-1-3-propylcarbonate)diol-   PHCN=Poly(hexamethylene carbonate)diol-   PEGA=Poly(diethylene glycol)adipate-   PTMO=Poly(tetramethylene Oxide)diol-   PDP=Diethylene Glycol-Ortho phthalic Anhydride polyester Polyol-   HHTPI=hydrogenated hydroxyl terminated polyisoprene-   C22=hydroxylterminated polydimethylsiloxanes block copolymer-   Poly(ethylene glycol)-block-poly(propylene    glycol))-block-Poly(ethylene glycol) polymer (“PEO-PPO-PEO Pluronic    polymers”)-   DDD=1,12-dodecanediol    Fluorinated End-Capping Groups-   C6-FOH═(CF₃)(CF₂)₅CH₂CH₂OH (1H,1H,2H,2H Perfluorooctanol)-   C8-FOH═(CF₃)(CF₂)₇CH₂CH₂OH (1H,1H,2H,2H Perfluorodecanol)-   C6-C8 FOH═(CF₃)(CF₂)₇CH₂CH₂OH and (CF₃)(CF₂)₅CH₂CH₂OH (Mixtures of-   C6-FOH and C8-FOH; also designated as BAL-D)-   C4-FOH═CHF₂(CF₂)₃CH₂OH (1H,1H,5H-perfluoro-1-pentanol)-   C3-FOH═(CF₃)(CF₂)₂CH₂OH (1H,1H Perfluorobutanol)    Non-Tin Based Catalyst-   Bi348—Bismuth Carboxylate Type 1-   Bi221—Bismuth Carboxylate Type 2-   Bi601—Bismuth Carboxylate Type 3

The bismuth catalysts listed above can be purchased from King Industries(Norwalk Conn.). Any bismuth catalyst known in the art can be used tosynthesize the SMMs of the invention.

EXAMPLE 1 General Synthetic Schemes for SMM4 and SMM6

Surface modifiers of the invention such as SMM4 and SMM6 may besynthesized by a 2-step convergent method according to the schemesdepicted in Schemes 1 and 2. Briefly, the polyisocyanate such asDesmodur N3200 or Desmodur 4470 is reacted dropwise with the surfaceactive group (e.g., a fluoroalkyl alcohol) in an organic solvent (e.g.anhydrous THF or dimethylacetamide (DMAC)) in the presence of a catalystat 25° C. for 2 hours. After addition of the fluorinated alcohol,stirring is continued for 1 hour at 50° C. and for a further 1 hour at70° C. These steps lead to the formation of a partially fluorinatedintermediate that is then coupled with the polyol (e.g.,hydrogenated-hydroxyl terminated polybutadiene, or poly(2,2dimethyl-1-3-propyl carbonate) diol) at 70° C. over a period of 14 hoursto provide the SMM. Because the reactions are moisture sensitive, theyare carried out under an inert N₂ atmosphere and anhydrous conditions.The temperature profile is also maintained carefully, especially duringthe partial fluorination, to avoid unwanted side reactions. The reactionproduct is precipitated in MeOH and washed several times with additionalMeOH. The catalyst residues are eliminated by first dissolving the SMMin hot THF or in hot IPA followed by reacting the SMM with EDTAsolution, followed by precipitation in MeOH. Finally, the SMM is driedin a rotary evaporator at 120-140° C. prior to use.

EXAMPLE 2 Synthesis of SMM5

All glassware were dried in the oven overnight at 110° C. To a 3-necked5000 mL reactor equipped with a stir bar and a reflux condenser wasadded 300 g (583 mmol) of Desmodur N3300. The mixture was degassedovernight at ambient temperature. Hydrogenated-hydroxyl terminatedpolybutadiene (HLBH polyol MW=2000) was measured into a 2000 mL flaskand degassed at 60° C. overnight. The bismuth catalyst K-Kat 348 (abismuth carboxylate; available from King Industries) was measured outinto a 250 mL flask and degassed overnight at ambient temperature. Theperfluorinated alcohol was measured into a 1000 mL flask and degassedfor 30 minutes at ambient temperature. After degassing, all the vesselswere purged with nitrogen.

300 mL of THF (or DMAC) was then added to the Desmodur N3300 containingvessel, and the mixture was stirred to dissolve the polyisocyanate.Similarly, 622 mL of THF was added to the HLBH polyol, and the mixturewas stirred to dissolve the polyol. Likewise, 428 mL of THF (or DMAC)was added to the perfluorinated alcohol and the mixture was stirred todissolve. Similarly for K-Kat 348 which was dissolved in 77 mL of THF orDMAC. Stirring was continued to ensure all the reagents were dissolvedin their respective vessels.

Half the K-Kat solution was transferred to the perfluorinated solutionwhich was stirred for 5 minutes. This solution was added to the reactionvessel containing the Desmodur N3300 solution dropwise over a period of2 hours at ambient (25° C.) temperature through a cannula (double endedneedle) under positive nitrogen pressure. After addition, thetemperature was raised to 50° C. for 1 hour and 70° C. for another 1hour. Proper stirring was maintained throughout. The remaining K-Kat 348catalyst was transferred to the HLBH-2000 flask; after stirring todissolve, this was added to the reactor containing the N3300. Thereaction mixture was allowed to react overnight for 14 hours at 70° C.to produce SMMS with 4 fluorinated end groups.

SMM/Polymer Admixture

The SMM solution was allowed to cool at ambient temperature. A 30 Lflask was filled with 15 liters of MeOH (methanol) and the polymersolution was slowly pored into this vessel with constant stirring for 10minutes, at which time the polymer began to precipitate out. The crudepolymer was allowed to settle, and the supernatant was siphoned out. Thepolymer was washed 2× with MeOH (5 L), each time with vigorous stirring.The polymer was redissolved in THF at 70° C., and an EDTA solution (240mL) was added. This was stirred at 70° C., after which another 240 mL ofEDTA solution was added. The heat was turned off, and the solution wasstirred for another 30 minutes. To this mixture 15 L of MeOH was slowlyadded to precipitate the polymer. The supernatant was carefully siphonedout and the washing was completed with the addition of two portions ofMeOH, using 5 L each time. The polymer was transferred to a rotaryevaporator and dried at 120-140° C. The purified polymer was stored inglass jars in a dessicator.

Examples of exemplary SMMs that can be prepared according to theprocedures described herein are illustrated in FIGS. 1 a-1 n.

EXAMPLE 3 Thermal Stability

The thermal degradation temperatures of the surface modifiers (SMM) weredetermined by a Thermogravimetric Analysis instrument (TGA).Thermogravimetric analysis (TGA) is often used to determine thermalstability by means of weight-loss decomposition profiles as a functionof temperature. This was carried out using a TA instruments TGA Q500(V6.3 Build 189 with autosampler) Thermogravimetric Analyzer operatingin Dynamic (High Resolution), Hi-Res™ mode <resolution: 4, max ramp: 50°C./min, max temp: 500° C.

Briefly, 20-50 mg of each sample was placed into 1004, platinum planssuspended from an analytical balance located outside the furnacechamber. After the balance was zeroed, the sample pan was heated fromambient to 500° C. in a Nitrogen atmosphere, N₂ (flow rate 40 cc/minbalance, 60 cc/min. furnace). The Hi-Res TGA mode varies the heatingrate as a function of sample weight loss rate, which allows the use ofhigh heating rates during no weight loss regions and reduced heatingrates at weight loss transitions to more accurately depict thedecomposition characteristics of the test sample. This techniqueimproves the reproducibility and resolution of onsets by separatingoverlapping or poorly defined events, and it eliminates the dependenceof decomposition behavior on the heating rate. A TGA plot indicating theweight loss and the rate of weight loss (or derivative) was plottedagainst the temperature using the Universal Analysis 2000 software (TAInstruments—Waters LLC, version 4.1D). If the material is completelydry, upon heating there is an onset (one or two depending upon thenature of the polymer) representing the start of degradation.

As an illustrative example, FIG. 2 shows the profile of SMM2 indicatinga first onset at a degradation temperature of T_(d1)=285° C.,representing a minor weight loss (−1%) due to fluoro-end groups and thehard segment (isocyanate linkage), followed by a major weight loss(−61%) at T_(d2)=397° C. due to the soft segment (polyol linkage) of theSMM.

FIGS. 2-8 show the thermal degradation pattern of various examples ofSMM having different chemistries. SMM2 (FIG. 2), SMM3 (FIG. 3), SMM 5(FIG. 4), SMM 7 (FIG. 5), SMM8 (FIG. 6), SMM10 (FIG. 7), and SMM 11(FIG. 8) are depicted by a High Resolution Thermogravimeteric Plot.Other thermal data and polymer characterization data, including TGA andEA results, are summarized in FIGS. 9A-9C.

EXAMPLE 4 Bulk Fluorine Analysis by Elemental Analysis (EA)

Bulk elemental (carbon, hydrogen, nitrogen, and fluorine) compositionwas analyzed by Galbraith Labs (Knoxyille, Tenn.) according to ASTM D5987 using a combustion elemental analyzer for carbon, hydrogen andnitrogen. Fluorine content was analyzed using an oxygen combustion bomband a fluoride ion-selective electrode to measure the fluoride ionsproduced by the absorption of fluorine vapor into a dilute base solutioninside the oxygen flask. Elemental fluorine from FIG. 9 indicates thatall the SMMs have good bulk fluorine >15%.

EXAMPLE 5 Surface Elemental Analysis by X-Ray Photoelectron Spectroscopy(XPS)

Carbothane™ (Thermedics Inc MA, USA), PE, and PP were used as controlpolymer and the base polymer. SMM admixtures prepared according toExample 2 were analyzed by XPS to determine the concentration of surfacefluorine (hydrophobic) as well as the urethane chemistries (polargroups). The measurements were performed at a single take-off angle of90° corresponding to a depth of 100 Å or at 20° corresponding to a depthof 10 Å, and a surface area of 4×7 mm² was analyzed. The films wereinvestigated for relative atomic percentages of fluorine (F), oxygen(O), nitrogen, carbon (C), and silicon (Si). Only the results of atomic% of fluorine (F), the element of interest, for 3 different basepolymers as modified with SMMs are provided as illustrations in Table 1and in FIG. 10. The data illustrate that SMM are compatible with a widerange of base polymers used in the medical industry.

TABLE 1 Compatibility of various SMMs possessing different chemistrieswith various polymers XPS, % Fluorine at 20° or 90° Base Polymer SMM1SMM2 SMM5 SMM11 SMM13 SMM14 Polyurethane 51 49 41 — — — Films Siloxane46 35 13 — — — Films Polypropylene 11 20 16 — — — Films Polyvinyl 32 4135 — — — Chloride Extruded Rods Polyamide — 19 15 11 12 11 (Nylon)Extruded rods Polysulfone — 9 — — — — Hollow Fibers

EXAMPLE 6 SMM Used in Nonwovens for Repellency

(i) Repellency of SMM-Modified SMM Used in Meltblown Nonwoven MeltblownFabric for Repellency.

SMMs were have been used in a meltblowing trial conducted on a 6″ pilotline using meltblowing grade polypropylene (PP MF650X from BasellPolyolefins) with a MFI=1200 g/10 min (230° C./2.16 kg). First, the SMMadditives were compounded into master batches and diluted toconcentrations of 2-3 weight % in the meltblowing process. Processingaids (e.g., commercially available low-molecular weight hydrocarbonpolymers) that can slow the crystallization rate of polypropylene wereused at 10 wt % to promote migration of the SMM additives. Nonwovenfabric was obtained in the meltblowing process conducted at 260° C. witha throughput of 0.4 g/hole/min. The nonwoven fabric produced was soft intexture, with a basis weight of ˜25 gsm and a fiber diameter of ˜3 μm.Repellency tests using various concentrations of 70% isopropanol (IPA)solutions were conducted on the fabric immediately after it emerged fromthe meltblowing process line. The fabric was again tested afterannealing at low temperatures in an air flow oven. The AmericanAssociation of Textile Chemists and Colorists (AATCC) standard testmethod 193-2005 was used for repellency testing of the fabric, with themodification that solutions were prepared in volumetric concentrationsinstead of ratios. FIG. 11 shows that (MB) fabric coming off the processline had minimal repellency (30% IPA repellency) but the repellencyincreased dramatically after annealing at low temperatures (70% IPArepellency after annealing at 60° C. and >75% IPA repellency afterannealing at 65° C. for 12 hours). After being subjected to a standardEtO sterilization cycle (54.4° C.), the meltblown fabric also showedrepellency to 70% IPA solution (FIG. 12).

FIG. 13 illustrates the repellency of treated and untreated nonwovenfabric. The control fabric (polypropylene without SMM treatment) showsno repellency as indicated by the passage of a drop of 70% IPA (wetting)whereas the fabric on the right shows remarkable repellency indicated bythe shape of the IPA droplet on the fabric without wetting. Heatexposure encountered during sterilization is sufficient to promotemigration of SMM additives, with no additional annealing required.

Furthermore, desired repellency of the fabric can also be achieved bybrief contact exposure (2-10 seconds) to temperatures of 100-130° C.Fabrics for medical garments may experience such conditions duringstandard manufacturing processes, such as drying of anti-statictreatments or calendar bonding of multilayer fabrics. FIG. 14illustrates repellency achieved on MB fabrics after brief, directcontact with hot plate surfaces at 100-130° C.

(ii) Repellency of SMM-Modified Nonwoven Spunbond Fabric

SMMs were used in a spunbond (SB) trial conducted on R&D prototypingequipment set up to mimic conditions of a spunbond pilot line.Specifically, a small-scale extruder with 4 temperature zones wasconnected to a metering pump and a die with 68 spinnerette holes. Theextruder was positioned on scaffolding above a guiding shaft thatdirected the extruded fibers into an attenuator gun supplied with highpressure air, which was used to stretch the extruded fibers. Theattenuated fibers were deposited on a moving mesh in a random fashion.The nonwoven webs thus formed were not bonded.

The SMMs were compounded into spunbond grade polypropylene (PP 3155 fromExxon Mobil) with a MFI=36 g/10 min (230° C./2.16 kg) at concentrationsof 1-2 wt % along with 5-10 wt % of a processing aid. The compoundedresins were extruded into spunbond nonwoven webs using the R&D equipmentat a process temperature of 230° C. at the die.

The spunbond webs were tested for repellency to IPA solutions afterannealing by direct contact for 5 seconds with a heated surface at 120°C. or after EtO sterilization of the nonwoven webs in a standard cycleat 54.4° C. FIG. 15 shows repellency to alcohol solutions withconcentrations as high as 80 vol % IPA can be achieved on spunbondfabrics modified with SMMs.

The results indicate the SMM synthesized have a very important utilityin providing alcohol (70% IPA) repellency to nonwoven (meltblown orspunbond) fabric.

Other Embodiments

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each independent publication or patent application was specificallyand individually indicated to be incorporated by reference.

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodifications and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure that come within known or customary practice withinthe art to which the invention pertains and may be applied to theessential features hereinbefore set forth, and follows in the scope ofthe claims.

Other embodiments are within the claims.

1. An admixture comprising a base polymer selected from polypropyleneand polyurethanes admixed with a surface modifier having a structureaccording to

wherein (i) A is a soft segment selected from poly(diethyleneglycol)adipate (PEGA), polytetramethylene oxide (PTMO),poly(ethyleneglycol)-block-poly(propyleneglycol))- block-poly(ethyleneglycol), or polydimethylsiloxane block copolymer (C22); (ii) B is a hardsegment comprising a urethane trimer or biuret trimer formed fromhexamethylene diisocyanate (HDI) biuret trimer, isophorone diisocyanate(IPDI) trimer, or hexamethylene diisocyanate (HDI) trimer, and B′, whenpresent, is a hard segment comprising a urethane; and (iii) each G is asurface active group comprising polyfluoroalkyls; wherein n is aninteger from 0 to 10; and wherein (i) said surface modifier has athermal degradation temperature of at least 200° C.; and (ii) saidadmixture is formed by mixing said surface modifier with said basepolymer to form a mixture and annealing said mixture; and wherein whenthe base polymer is polypropylene, A is a soft segment selected frompolymethylsiloxane block copolymer (C22) andpoly(ethyleneglycol)-block-poly(propyleneglycol)-block-poly(ethyleneglycol).2. The admixture of claim 1, wherein said surface active group isselected from the group consisting of radicals of the general formulaCH_(m)F_((3-m))(CF₂)_(r)CH₂CH₂— and CH_(m)F_((3-m))(CF₂)_(s)(CH₂CH₂O)χ—,wherein m is 0, 1, 2, or 3; χ is an integer between 1-10; r is aninteger between 2-20; and s is an integer between 1-20.
 3. The admixtureof claim 2, wherein m is 0 or
 1. 4. The admixture of claim 1, whereineach surface active group is selected, independently, from(CF₃)(CF₂)₅CH₂CH₂O—, (CF₃) (CF₂)₇CH₂CH₂O—, CHF₂(CF₂)₃CH₂O—, and(CF₃)(CF₂)₂CH₂O—.
 5. The admixture of claim 1, wherein said surfacemodifier has a theoretical molecular weight of less than 10,000 Daltons.6. The admixture of claim 1, wherein A is poly(tetramethylene oxide)(PTMO).
 7. The admixture of claim 1, wherein A is polydimethylsiloxaneblock copolymer.
 8. The admixture of claim 7, wherein n is 0, and B isformed from hexamethylene diisocyanate (HDI) biuret trimer.
 9. Theadmixture of claim 1, wherein A is formed frompoly(ethyleneglycol)-block-poly(propyleneglycol))-block-poly(ethyleneglycol).
 10. The admixture of claim 9, wherein n is 0, and B is formedfrom isophorone diisocyanate (IPDI) trimer.
 11. The admixture of claim1, wherein A is poly(diethylene glycol)adipate (PEGA).
 12. The admixtureof claim 11, wherein n is 0, and B is formed from isophoronediisocyanate (IPDI) trimer.
 13. The admixture of claim 1, wherein saidbase polymer is selected from polypropylene.
 14. The admixture of claim1, wherein said base polymer is selected from, polyurethanes.
 15. Theadmixture of claim 1, wherein said admixture is melt processed prior toannealing.
 16. An article comprising the admixture of claim
 1. 17. Thearticle of claim 16, wherein said article is a filter, film, fiber,sheet, or an implantable medical device.
 18. The article of claim 17,wherein said implantable medical device is a cardiac-assist device, acatheter, a stent, a prosthetic implant, an artificial sphincter, or adrug delivery device.
 19. The article of claim 16, wherein the basepolymer is polypropylene.
 20. The article of claim 16, wherein saidarticle is a hollow fiber membrane.
 21. The article of claim 16, whereinsaid article is a filter.
 22. The article of claim 16, wherein saidarticle is a tube.
 23. The article of claim 16, wherein said article isa conduit.
 24. The article of claim 16, wherein said article is formedfrom an admixture that is melt-processed.
 25. The article of claim 24,wherein said admixture is molded, melt blown, melt spun, or meltextruded.
 26. The article of claim 16, wherein the base polymer isselected from polyurethanes.
 27. The admixture of claim 1, wherein n is0, A is poly(tetramethylene oxide)(PTMO), B is formed from hexamethylenediisocyanate (HDI) biuret trimer, and said base polymer is apolyurethane.
 28. The admixture of claim 1, wherein n is 0, A ispolydimethylsiloxane block copolymer, B is formed from hexamethylenediisocyanate (HDI) biuret trimer, and said base polymer ispolypropylene.